Elucidating dislocation core structures in titanium nitride through high-resolution imaging and atomistic simulations

• DOI: 10.1016/j.matdes.2022.111327
• Publication Date: 2022-10-27T23:09:48Z
• Authors: J. Salamania; D.G. Sangiovanni; A. Kraych; K.M. Calamba Kwick; I.C. Schramm; L.J.S. Johnson; R. Boyd; B. Bakhit; T.W. Hsu; M. Mrovec; L. Rogström; F. Tasnádi; I.A. Abrikosov; M. Odén
• Keywords: Condensed Matter - Materials Science; Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences; 02 engineering and technology; 01 natural sciences; Annan materialteknik; 0103 physical sciences; TA401-492; Other Materials Engineering; 0210 nano-technology; Materials of engineering and construction. Mechanics of materials

Although titanium nitride (TiN) is among the most extensively studied and thoroughly characterized thin-film ceramic materials, detailed knowledge of relevant dislocation core structures lacking. By high-resolution scanning transmission electron microscopy (STEM) epitaxial single crystal (001)-oriented TiN films, we identify different types their structures. These include, besides expected primary full a/2{110}<1$\bar{1}$0> dislocation, Shockley partial dislocations a/6{111}<11$\bar{2}$> sessile Lomer edge a/2{100}<011>. Density-functional theory classical interatomic potential simulations complement STEM observations by recovering atomic structure types, estimating Peierls stresses, providing insights on chemical bonding nature at core. The generated models cores suggest locally enhanced metal-metal bonding, weakened Ti-N bonds, N vacancy-pinning that effectively reduces mobilities {110}<1$\bar{1}$0> {111}<11$\bar{2}$> dislocations. Our findings underscore presence effects should be considered in design interpretations nanoscale macroscopic properties TiN.